The Basilisk

The Basilisk is the first boss you will confront in Trine 2, which would usually mean it's the easiest to defeat. Is that the case here? Yes.

The basilisk's only real attack is that it spits fire at you. There are three platforms holding up the ceiling in this room, allow the boss to destroy the first, then take out the other two using the Thief's grappling hook to reach them. Easy enough? Yes, but there will be other Goblins who appear after the first platform is destroyed. Whether you kill them or not is up to you.

This boss is made even easier in multiplayer. One player can focus on destroying the platforms while the others focus on the waves of Goblins.